Cam hinge assembly

ABSTRACT

A CAM HINGE ASSEMBLY SUITABLE FOR BOTH RETAINING A DOOR IN THE OPEN POSITION AND ALSO FOR AUTOMATICALLY CLOSING THE DOOR, COMPRISING A HOUSING HAVING A FLOOR AND AT LEAST ONE FLANGE EXTENDING AT RIGHT ANGLES ABOVE THE SAID FLOOR, A STATIONARY CAM ASSEMBLY PIVOTALLY ASSOCIATED WITH THE SAID HOUSING FLOOR AND PROVIDED WITH A SPRING ENGAGING LUG, PORTIONS OF THE SAID CAM ASSEMBLY BINDING AGAINST THE SAID FLANGE WHEN THE DOOR IS ROTATED TO THE OVER-OPEN POSITION AND A COIL SPRING OPERATIVELY CONNECTED TO THE SAID CAM ASSEMBLY AT THE SAID LUG, THE SAID SPRING ACTING TO ROTATE THE SAID DOOR ABOUT A CAM ASSEMBLY PIVOT TO THEREBY BIAS THE DOOR EITHER TO ITS CLOSED POSITION OR TO ITS OVER-OPEN POSITION.

Sept. 28, 1971 Filed Jun 9, 1969 2 Sheets-Sheet l [Ll l/l/ ///l 24 INVENTORS.

26 JOHN A. HEYER WILLIAM H.WRIGHT WILLIAM J.5TAHLER FIG.4

Sept. 28, 1971 J. A. HEYER ETAL CAM HINGE ASSEMBLY Filed June 9. 1969 2 Sheets-Sheet 2 FIGS m ML H IA .RRT w s E J QHMM MAAM EN L VHMW mww 4 4 lavh j f sdu gk v ATTORNEY United States Patent Filed June 9, 1969, Ser. No. 831,496 Int. Cl. Ef 1/12 US. Cl. 16-190 8 Claims ABSTRACT OF THE DISCLOSURE A cam hinge assembly suitable for both retaining a door in the open position and also for automatically closing the door, comprising a housing having a floor and at least one flange extending at right angles above the said floor, a stationary cam assembly pivotally associated with the said housing floor and provided with a spring engaging lug, portions of the said cam assembly binding against the said flange when the door is rotated to the over-open position and a coil spring operatively connected to the said cam assembly at the said lug, the said spring acting to rotate the said door about a cam assembly pivot to thereby bias the door either to its closed position or to its over-open position.

This invention relates to the general field of door hardware, and more particularly, is directed to a self-contained, spring biased hinge assembly including cam operating means.

The present invention is directed to a novel cam hinge assembly which finds particular utility in those industries wherein it is desirable to maintain a cabinet door in both the open position during certain periods of use and also to automatically close the door during other periods of use. The present cam hinge assembly may be readily adapted for use with heavy cabinet doors such as commercial refrigerator doors, commercial freezer doors and similar constructions wherein door hinge devices capable of both holding the door open and also to automatically close the door are desirable.

Prior workers in the field have employed assemblies designed to maintain a cabinet door in open position and also to urge the door to closed position by utilizing constructions such as a cam surface designed to ride upon either a spring biased platform or optionally, upon a resilient leaf spring as dictated by the position of the door. We are also aware of a hinge construction wherein a bracket is carried by the door and is provided with pins located at diagonally opposite corners and which is provided with an arm which affixes to the cabinet and cooperates with a spring. The spring biases between portions of the hinge construction to urge the door into either closed or fully opened position by locating the spring either to the right or to the left of a straight line relation with regard to the pins.

The prior art models of which we are familiar are generally satisfactory in use but are all extremely complicated in construction and therefore costly from the standpoint of manufacture, installation and maintenance. Further, none of the prior art hinge assembly designs are capable of also serving as an overstop to thereby prevent damage to the hinge assembly or to the spring construction as is taught by the present application.

It is therefore an object of the present invention to pro vide an improved cam hinge assembly of the type set forth.

It is another object of the present invention to provide a novel cam hinge assembly incorporating a flanged housing and a stationary cam assembly rotatively operable in cooperation with the said housing.

ice

It is another object of the present invention to provide a novel cam hinge assembly including means to prevent the concentration of stresses in the coil spring.

It is another object of the present invention to provide a spring operable cam hinge assembly capable of optionally biasing a door to either the closed position or to an over-open position.

It is another object of the present invention to provide a novel cam hinge assembly that is rugged in construction, simple in design and trouble-free when in use.

Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment thereof, taken in conjunction with the accompanying drawings wherein like reference characters refer to similar parts throughout the several views and in which:

FIG. 1 is a top plan view of a cam hinge assembly constructed in accordance with the present invention and showing the door in closed position.

FIG. 2 is a partial, top plan view similar to FIG. 1 and showing the position of the operating parts with the door in open position.

FIG. 3 is an exploded, perspective view of the operating portions of the cam assembly.

FIG. 4 is a side elevational view of the cam assembly with the door in closed position.

FIG. 5 is a side elevational view, partly broken away illustrating the construction of the coil spring.

FIG. 6 is an exploded, perspective view of the cam assembly and hinge bracket.

FIG. 7 is a partial, top plan view similar to FIG. 1 showing the relative positions of the door and cam assembly with the door in ninety degree open position.

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of our invention selected for illustration in the drawings and are not intended to define or limit the scope of the invention.

Referring now to FIGS. 1 and 2, we show a cam hinge assembly generally designated 10 as applied to a pivotally connected door 12 such as may generally be used in conjunction with a refrigerator or freezer cabinet 14. In use, the hinge assembly 10 is normally fully enclosed within the door 12 with only the pivot pin 16 extending below the door construction for pivotal operation as hereinafter more fully set forth. In view of the inaccessible location of the hinge assembly, the stress relieved construction employed to prolong spring life as hereinafter set forth in detail is of primary importance.

As best observed in FIG. 3, the bottom of the cabinet door outer shell 18 is drilled to provide a bottom opening 20 to receive the cam connected pivot pin 16 therethrough for door operating purposes. The pivot pin 16 stationarily affixes to the cabinet connected hinge bracket 22 and is retained therein by the combination square pin bottom 72, the square bracket hole 74, the washer 24 and the retaining screw 26.

The bearing block bracket 28 bottomly positions within the door outer shell 18 with its bottom hole 30 aligned over the door bottom opening 20 to permit passage of the pivot pin 16 therethrough. A flanged side 32 rises above the bracket floor 34 of the bearing block bracket 28 and extends at right angles thereto to thereby provide a cam binding construction as hereinafter more fully explained to prevent over-opening of the door 12. The bearing block 34 secures within the bearing block bracket 28 in conventional manner such as by the machine screw 36 and is provided with a pivot pin receiving opening 38 at one end thereof in alignment with the aligned bottom openings 20, 30 which are provided respectively in the door shell 18 and the bracket .28. A bearing 40 of nylon or other suitable material inserts within the bearing block pivot pin receiving opening 3 8 to rotatively receive the cam assembly pivot pin 16 in the usual manner to permit rotative engagementt herein. A retaining ring 42 positions between the door construction 18 and the bottom of the bearing block 34 and serves to maintain the pivot pin within the bearing 40 as the door 12 swings through all rotative positions of operation.

As best observed in FIGS. 3 and 4, the spring retainer bracket 44 afiixes to the top of the bearing block 34 in conventional manner such as by employing the machine screws 46, 48 which threadedly fasten within the respective, aligned connection holes 50, 52 and 54-, 56. The spring retainer bracket 44 forwardly overhangs the bearing block 34 and terminates forwardly in an upwardly bent flange 58 which serves as the forward spring retainer in conjunction with the spring receiving opening 60 provided therein.

The cam assembly 62 includes a generally flat, rounded cam body 64 which may be cast or otherwise formed to provide an integral pivot pin 16 depending from the under body surface 66 and the integral rear spring retainer pin 68 rising above the top body surface 70. It should be noted that the pivot pin 16 and the rear spring retainer pin 68 axially offset from the cam body 64 to form a crank for door operational purposes as hereinafter more fully set forth. The pivot pin 16 terminates downwardly in a square construction 72 sized to fit within the square hole 74 which is provided in the stationary hinge bracket 22. In this manner, the entire cam assembly 62 is maintained in stationary relationship with the stationary hinge bracket 22 and the door 12 to rotate about the stationary pivot pin 16 by means of the pivot pin bearing 40 to thereby bias the spring 76.

As best seen in FIG. 5, the hinge assembly spring 76 is fabricated as a tightly coiled extension spring having a body section 82 formed of a plurality of tight helically wound coils 86 of equal diameter. The body section 82 terminates laterally in spaced, coned ends 78, 80 which are integrally formed with the body coils 86 and concentrically reduce in diameter to form the frusto-conical shaped ends 78, 80 as illustrated. Each spring end 78, 80 terminates in an end coil 88, 90 of reduced diameter of size just sufficient to receive the respective swivel hook extension rods 92, 94 in sliding engagement therein. Each respective extension rod 92, 94 inserts at one end thereof through the openings 98, 100 formed by each end coil 88, 90 and terminates inwardly in a widened base 96 having dimensions greater than the spring end openings 98, 100 to thereby prevent the swivel hook extension rods 92, 94 from pulling free from the spring construction 76 during periods of operation. Each swivel extension rod 92, 94 terminates outwardly in a bent hook 102, 104 which respectively bend gradually through an associated transition piece 106, 108. The transition pieces 106, 108 are provided to eliminate high stress concentration points which may be built into the extension rods 92, 94 by bending the hooks 102, 104 too sharply.

It should be noted that the widened bases 96 serve to facilitate unstressed flexing between the extension rods 92, 94 and the spring coned ends 78, 80. The absolute sep aration of the parts completely eliminates any stress concentration points between the extension rods 92, 94 and the spring 76 to thereby facilitate maintenance free operation and to assure extended periods of spring life. It should be noted that the separate extension rods 92, 9'4 serve to axially extend the spring 76 without any buildup of stress concentration. Accordingly, the parts 76, 92, 94 function to mutually flex upon operation and have no tendency to break apart.

In order to use our invention, the bearing block bracket 28, the bearing block 34, the bearing 40, the retaining ring 42, the spring retainer bracket 44 and the cam assembly 62 are positioned at the bottom of the door outer shell 18 with the cam pivot pin 16 projecting through the door bottom opening as indicated in FIGS. 3 and 4.

The square pivot pin construction 72 inserts within the rectangular hole 74 provided in the stationary hinge bracket 22 and is retained therein by means of the machine screw 26 to thereby firmly affix the door 12 to the hinge bracket 22 with the cam assembly secured in stationary relationship to the refrigerator or other cabinet construction 14. A hinge assembly spring 76 of the tightly wound, coiled extension type of size to tension between the cam retainer pin 68 and the spring retainer flange 5'8 secures in position by engagement of the hook 104 upon the cam retainer pin 68 and the hook 102 upon the spring receiving opening 60.

As best observed in FIGS. 1, 2 and 7, the cam assembly 62 remains in stationary relationship to the stationary hinge bracket 22 during all rotative positions of door operation from completely closed as in FIG. 1 to the overopen position of FIG. 2. It will be observed that as the door construction 18 turns about the bearing 40 and rotates with relation to the cam assembly 62 from the closed position of FIG. 1 to the ninety degree open position of FIG. 7, the straight line distance between the bent flange 58 and the cam spring retainer pin 68 increases to thereby increasingly tension the spring 76. As may be perceived in FIGS. 1 and 7, the crank moment arm between the cam pivot pin 16 and the cam rear spring retainer pin 68 serves to inwardly offset the longitudinal axis of the spring 76 with respect to the axis of the door. A force vector perpendicular to the axis of the spring is thus created which functions to continually urge the door 12 into the closed position of FIG. 1 due to the bias of the spring 76 operating through the crank arm between the pins 16, 68. When the door is opened exactly to ninety degrees as is illustrated in FIG. 7, the axis of the spring 76 aligns with the axis of the door 12 and further aligns with a line drawn through the pins 16, 68 to thereby eliminate all side force vectors. Thus the spring 76 will neither urge the door to the closed position of FIG. 1 or to the over-open position of FIG. 2.

Once the door 12 turns past the ninety-degree open position, the bias of the spring 76 functions through the crank are created by the cam connected pins 16, 68 to thereby create a force vector perpendicular to the axis of the door 12 which tends to further open the door. In this position, as best seen in FIG. 2, the side surface 106 of the cam assembly 62 binds against the flanged side 32 of the bearing block bracket 28 to thereby prevent further opening of the door 12 with respect to the cabinet construction 14. We have found an angle opening of approximately one hundred and seven degrees before binding of the cam side 106 against the flange 32 to be satisfactory for this purpose.

Thus, a cam hinge assembly has been provided having extremely simple construction with few moving parts. The cam and spring assembly as herein described serves to close the door 12 when it is opened to less than ninety degrees and also functions to maintain the door in open position once it has been turned past the ninety-degree open position. Additionally, the cam assembly is employed against cooperating hinge members to thereby prevent the door from over-opening. The cam hinge assembly may be precisely designed to maintain the door opening to an exact rotative position, for example one hundred and seven degrees.

Although we have described our invention with a certain degree of particularity, it is understood that the present disclosure has been made only by Way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

We claim:

1. In a cam hinge assembly for pivotally operating a door about a fixed hinge bracket from a closed position to an open position, the combination of (A) a cam assembly immovably affixed to the said hinge bracket,

(1) said cam assembly having associated door pivoting construction, and

(2) said cam assembly having spring retaining means;

(B) bearing block means positioned within the said door and rotatively associated with the said cam assembly,

(1) said bearing block means carrying spring retaining means thereon;

(C) a coil spring tensioned between the said cam assembly spring retaining means and the said bearing block spring retaining means 1) said coil spring having a longitudinal axis;

and

(D) crank means associated with the said cam assem- (l) the said crank means increasingly tensioning the said spring as the said door is rotated from closed position to a ninety degree open position.

2. The invention of claim 1 wherein the said crank means create a force vector perpendicular to the longitudinal axis of the spring which tends to close the said door when in all angular positions from closed to slightly less than ninety degrees open.

3. The invention of claim 1 wherein the said crank means serve to create a force vector tending to keep the said door open when the door is turned past the ninetydegree open angular position.

4. The invention of claim 1 wherein the said crank means include means to prevent the said door from overopening.

'5. The invention of claim 1 wherein the said bearing block means includes flange means to prevent the said door from over-opening, said flange means including a flanged construction positioned to bind against portions of the said cam assembly when the door rotates to a designed over-open position.

6. The invention of claim 1 wherein the said cam as sembly includes a relatively flat rounded body, said door pivoting construction depending from the bottom of the said body and said spring retaining means extend upwardly from the top of the said body.

7. The invention of claim 1 wherein the said cam assembly includes a relatively flat rounded body, said door pivoting construction depending from the bottom of the said body and said spring retaining means extend upwardly from the top of the said body, door pivoting construction offsetting from the said spring retaining means a distance sufficient to form the said crank means.

8. The invention of claim 1 wherein the said cam assembly includes a relatively flat rounded body, said door pivoting construction depending from the bottom of the said body and said spring retaining means extend upwardly from the top of the said body, the axis of the said spring overlying a line drawn through the said door pivoting construction and the said spring retaining means when the door is rotatively opened to exactly ninety degrees from the said closed position.

References Cited UNITED STATES PATENTS 529,101 11/1894 Bauer 16-80 1,854 11/1840 Smith 16-80 FOREIGN PATENTS 13,606 6/1907 Great Britain M 16 416,828 12/1946 Italy 16-72 BOBBY R. GRAY, Primary Examiner P. A. ASCHENBRENNER, Assistant Examiner US. Cl. X.R. 

